1. Chapter 29 Cardiac Arrest

2. © 2005 by Thomson Delmar Learning,a part of The Thomson Corporation. All Rights Reserved 2 Overview  The History of Defibrillation  Survival from Cardiac Arrest  Automated External Defibrillator  Heart’s Electrical Activity

3. © 2005 by Thomson Delmar Learning,a part of The Thomson Corporation. All Rights Reserved 3 Overview  Dysrhythmia  Assessment  Management  Postcall

4. © 2005 by Thomson Delmar Learning,a part of The Thomson Corporation. All Rights Reserved 4 The History of Defibrillation  One of the most common causes of cardiac arrest is ventricular fibrillation (VF)  VF can only be treated by electrical countershock

5. © 2005 by Thomson Delmar Learning,a part of The Thomson Corporation. All Rights Reserved 5 The History of Defibrillation  Defibrillator: machine used to deliver a shock  Defibrillation: process of delivering shocks to the heart

6. © 2005 by Thomson Delmar Learning,a part of The Thomson Corporation. All Rights Reserved 6 The History of Defibrillation  Original ones were large and restricted exclusively to the operating room –Initially impractical for emergency use –Required patient’s chest to be opened and the heart exposed

7. © 2005 by Thomson Delmar Learning,a part of The Thomson Corporation. All Rights Reserved 7 The History of Defibrillation  Transition –1956: Dr. Zoll created first external defibrillator External defibrillator remained in the hospital due to its large size EMS relied solely on CPR

8. © 2005 by Thomson Delmar Learning,a part of The Thomson Corporation. All Rights Reserved 8 The History of Defibrillation  Transition –1980: Dr. Eisenberg began a prehospital defibrillation program EMTs used one of the first AEDs in Seattle, Washington

9. © 2005 by Thomson Delmar Learning,a part of The Thomson Corporation. All Rights Reserved 9 Survival from Cardiac Arrest  Reversal of cardiac arrest –Use of an AED is only one part of the formula for a successful reversal of cardiac arrest –Time is of the essence Every minute of delay in calling EMS or getting a defibrillator to the patient decreases the chance that the heart will respond to the shock –Chain of survival

10. © 2005 by Thomson Delmar Learning,a part of The Thomson Corporation. All Rights Reserved 10 Survival from Cardiac Arrest  Chain of survival –Early access –Early CPR –Early defibrillation –Early advanced cardiac life support

11. © 2005 by Thomson Delmar Learning,a part of The Thomson Corporation. All Rights Reserved 11 Survival from Cardiac Arrest  If CPR is provided in less than 4 minutes and defibrillation is provided in less than 8 minutes, the patient has a 43% chance of survival

12. © 2005 by Thomson Delmar Learning,a part of The Thomson Corporation. All Rights Reserved 12 Survival from Cardiac Arrest  For every minute that defibrillation is delayed to the patient, the chances of survival decrease by at least 10%  In the situation of cardiac arrest, every minute counts

13. © 2005 by Thomson Delmar Learning,a part of The Thomson Corporation. All Rights Reserved 13 Early defibrillation saves lives.

14. © 2005 by Thomson Delmar Learning,a part of The Thomson Corporation. All Rights Reserved 14  Components –Two large electrodes: pads placed on patient’s chest –Cables (leads): connect patient to the machine Automated External Defibrillator

15. © 2005 by Thomson Delmar Learning,a part of The Thomson Corporation. All Rights Reserved 15 Automated External Defibrillator  Components –Battery source: generates electricity used to perform the defibrillation –Internal computer: samples the heart’s electrical rhythm through sensors in the electrodes

16. © 2005 by Thomson Delmar Learning,a part of The Thomson Corporation. All Rights Reserved 16

17. © 2005 by Thomson Delmar Learning,a part of The Thomson Corporation. All Rights Reserved 17  Single largest advantage: does not require operator to learn the complex rules of electrocardiogram interpretation  Can interpret the rhythm and advise EMT to shock if appropriate Automated External Defibrillator

18. © 2005 by Thomson Delmar Learning,a part of The Thomson Corporation. All Rights Reserved 18  AED equipment check –Case –Cables –Electrodes Should be sealed and not expired Automated External Defibrillator

19. © 2005 by Thomson Delmar Learning,a part of The Thomson Corporation. All Rights Reserved 19  AED equipment check –Batteries Have backup batteries Keep batteries recharged –Supplies 4 by 4 gauze or towel Razor or bandage scissors –Document Automated External Defibrillator

20. © 2005 by Thomson Delmar Learning,a part of The Thomson Corporation. All Rights Reserved 20 Stop and Review  What is the definitive treatment for cardiac arrest due to VF?  What role does CPR have in the chain of survival?

21. © 2005 by Thomson Delmar Learning,a part of The Thomson Corporation. All Rights Reserved 21 Cardiac Arrest  A common consequence of acute myocardial infarction (AMI) is cardiac arrest and death  Sudden cardiac death (SCD): the unexpected cessation of heartbeat within 2 hours of the onset of chest pain  More than 50% of SCD cases occur outside of the hospital

22. © 2005 by Thomson Delmar Learning,a part of The Thomson Corporation. All Rights Reserved 22 Cardiac Arrest  Signs and symptoms –Chest pain –Cardiac symptoms –AMI can lead to Congestive heart failure Cardiogenic shock Sudden cardiac death

23. © 2005 by Thomson Delmar Learning,a part of The Thomson Corporation. All Rights Reserved 23 Heart’s Electrical Activity  Every heartbeat has an electrical event that preceded the mechanical event  A normal electrical event within the heart is the propagation of electrical impulses from the SA node to the ventricles  ECG: graphical illustration of electrical activity from the heart as detected by an ECG machine

24. © 2005 by Thomson Delmar Learning,a part of The Thomson Corporation. All Rights Reserved 24 An electrical impulse from the SA node travels to the AV node and the ventricle, causing the ventricle to contract and creating a pulse.

25. © 2005 by Thomson Delmar Learning,a part of The Thomson Corporation. All Rights Reserved 25 Heart’s Electrical Activity  Normal sinus rhythm –Complexes: grouped waves –Regularly repeating complexes are seen as a rhythm on the ECG

26. © 2005 by Thomson Delmar Learning,a part of The Thomson Corporation. All Rights Reserved 26 Heart’s Electrical Activity  Normal sinus rhythm –SA node: natural source of a normal cardiac complex –Normal sinus rhythm: electrical rhythm seen when the heart’s electrical system functions properly

27. © 2005 by Thomson Delmar Learning,a part of The Thomson Corporation. All Rights Reserved 27 Normal sinus rhythm.

28. © 2005 by Thomson Delmar Learning,a part of The Thomson Corporation. All Rights Reserved 28 Heart’s Electrical Activity  Escape pacemakers –SA node: the heart’s pacemaker –Automaticity: heart muscle’s ability to self-pace –Escape rhythm: resulting rhythm that may provide patient with enough blood flow to stay alive until a physician inserts an artificial pacemaker

29. © 2005 by Thomson Delmar Learning,a part of The Thomson Corporation. All Rights Reserved 29 Dysrhythmia  Any disruption of the normal sinus rhythm  Heart muscle is irritable and fires chaotically

30. © 2005 by Thomson Delmar Learning,a part of The Thomson Corporation. All Rights Reserved 30 Dysrhythmia  PVCs –Can disturb blood flow –Are felt as an irregular pulse –Can indicate ventricular irritability –Can progress to more potentially lethal complications

31. © 2005 by Thomson Delmar Learning,a part of The Thomson Corporation. All Rights Reserved 31 Dysrhythmia  Ventricular tachycardia (VT) –Ventricular rate of between 100 to 250 bpm –Does not allow enough time for blood to fill and then empty –Results in little to no blood flow to the body

32. © 2005 by Thomson Delmar Learning,a part of The Thomson Corporation. All Rights Reserved 32 Dysrhythmia  Ventricular tachycardia (VT) –Pulses are quickly lost; loss of consciousness ensues –MUST DEFIBRILLATE!

33. © 2005 by Thomson Delmar Learning,a part of The Thomson Corporation. All Rights Reserved 33 Ventricular Tachycardia  Watch this animation demonstrating ventricular tachycardia.

34. © 2005 by Thomson Delmar Learning,a part of The Thomson Corporation. All Rights Reserved 34 Dysrhythmia  Ventricular fibrillation (VF) –Extensive area of damage from an AMI can lead to VF –VF is a chaotic firing of multiple ventricular cells that results in no organized rhythm –During VF, the heart simply quivers and does not create any forward blood flow –MUST DEFIBRILLATE!

35. © 2005 by Thomson Delmar Learning,a part of The Thomson Corporation. All Rights Reserved 35 Ventricular Fibrillation  Watch this animation demonstrating ventricular fibrillation.

36. © 2005 by Thomson Delmar Learning,a part of The Thomson Corporation. All Rights Reserved 36 Dysrhythmia  Asystole –Arrhythmia with no electrical activity is left ECG will be flatline Defibrillation will have no practical value –Without a coordinated rhythmic contraction, blood flow stops and pulses are lost –Without quick defibrillation, the myocardium will suffer irreversible damage from lack of oxygen

37. © 2005 by Thomson Delmar Learning,a part of The Thomson Corporation. All Rights Reserved 37 Asystole  Watch this animation demonstrating asystole.

38. © 2005 by Thomson Delmar Learning,a part of The Thomson Corporation. All Rights Reserved 38 Dysrhythmia  Pulseless electrical activity (PEA) –Despite normal-looking electrical activity on an ECG, a patient may still have cardiac compromise –Observe the patient, not the monitor

39. © 2005 by Thomson Delmar Learning,a part of The Thomson Corporation. All Rights Reserved 39 Dysrhythmia  Pulseless electrical activity (PEA) –If no pulse, begin CPR despite ECG findings –PEA is not treated by defibrillation

40. © 2005 by Thomson Delmar Learning,a part of The Thomson Corporation. All Rights Reserved 40 Assessment  Begin with scene size-up  Initial assessment –Cardiac arrest management focuses on ABCs and CPR

41. © 2005 by Thomson Delmar Learning,a part of The Thomson Corporation. All Rights Reserved 41 Assessment  History –Try to gather a history It will be useful to both advanced providers and hospital personnel

42. © 2005 by Thomson Delmar Learning,a part of The Thomson Corporation. All Rights Reserved 42 Assessment  Scene size-up –Always address scene safety –Fluids are a hazard to an EMT using an AED Can transmit electrical energy to EMT instead of to patient

43. © 2005 by Thomson Delmar Learning,a part of The Thomson Corporation. All Rights Reserved 43 Assessment  Scene Size-up –Remove wet patient to a dry place Towel dry before defibrillating –Never defibrillate a patient who is lying in a puddle of liquid

44. © 2005 by Thomson Delmar Learning,a part of The Thomson Corporation. All Rights Reserved 44 Before using the AED, make sure the scene is safe.

45. © 2005 by Thomson Delmar Learning,a part of The Thomson Corporation. All Rights Reserved 45 Assessment  General impression –Does dispatch information match what is observed on-scene? –Get the global picture? –Is the telephone off the hook? –Open medication bottles?

46. © 2005 by Thomson Delmar Learning,a part of The Thomson Corporation. All Rights Reserved 46 Assessment  Where is the patient? –In a chair? –Lying on the ground? –If no one witnessed the patient collapse, consider spinal precautions

47. © 2005 by Thomson Delmar Learning,a part of The Thomson Corporation. All Rights Reserved 47 Assessment  Initial assessment –Take spinal precautions if trauma suspected –Determine level of consciousness –Check ABCs

48. © 2005 by Thomson Delmar Learning,a part of The Thomson Corporation. All Rights Reserved 48 Assessment  Initial Assessment –If patient is not breathing, give two breaths and check pulse –If no pulse, prepare AED –If delay in getting AED prepared, start CPR

49. © 2005 by Thomson Delmar Learning,a part of The Thomson Corporation. All Rights Reserved 49 Management  Attachment of AED –Attach electrodes to chest Attach electrode pads to the cables Place one pad under the patient’s right clavicle and the other on the patient’s lower left rib cage –Or place one on the anterior chest and one on the posterior

50. © 2005 by Thomson Delmar Learning,a part of The Thomson Corporation. All Rights Reserved 50 Management  Attachment of AED –Attach electrodes to chest Consult diagram on AED or on electrodes for placement Cables are color coded –White cable and pad go to right clavicle –Red cable and pad are attached to the lower left rib cage

51. © 2005 by Thomson Delmar Learning,a part of The Thomson Corporation. All Rights Reserved 51 There are two acceptable positions for the AED pads: A. anterior- anterior or B. anterior-posterior.

52. © 2005 by Thomson Delmar Learning,a part of The Thomson Corporation. All Rights Reserved 52 Management  Preparation –Once AED has been attached, turn power on –Press Analyze If CPR is in progress, discontinue. Usual command is “All clear!” Motion from CPR can create motion artifact, causing AED to mistakenly identify the ECG as VF

53. © 2005 by Thomson Delmar Learning,a part of The Thomson Corporation. All Rights Reserved 53 Management  Preparation –If machine detects a shockable rhythm, it will automatically charge –While machine charges, call “All clear!” again

54. © 2005 by Thomson Delmar Learning,a part of The Thomson Corporation. All Rights Reserved 54 Management  Defibrillation –Shout: “I’m clear, you’re clear, we’re all clear!” –Press Shock button to defibrillate –Press Analyze again

55. © 2005 by Thomson Delmar Learning,a part of The Thomson Corporation. All Rights Reserved 55 AED Used in the Field  Watch this video clip to see how an AED is used in the field.

56. © 2005 by Thomson Delmar Learning,a part of The Thomson Corporation. All Rights Reserved 56 Management  Shocks –Shocks are delivered in sets of three repeated, or stacked, shocks. –Goal: deliver three stacked shocks within 1 minute

57. © 2005 by Thomson Delmar Learning,a part of The Thomson Corporation. All Rights Reserved 57 Management  Shocks –No need to check pulse between shocks –Check pulses at the beginning and the end of the stacked shocks

58. © 2005 by Thomson Delmar Learning,a part of The Thomson Corporation. All Rights Reserved 58 Management  Analysis –Once defibrillation sequence has ended, check again for pulse and breathing –If none is present, resume CPR

59. © 2005 by Thomson Delmar Learning,a part of The Thomson Corporation. All Rights Reserved 59 Special Situations  Artificial pacemakers –Don’t place pads over pacemaker –Move it slightly to the left and down several inches toward the feet

60. © 2005 by Thomson Delmar Learning,a part of The Thomson Corporation. All Rights Reserved 60 Special Situations  Automatic implantable defibrillator –Don’t place pads over the implantable defibrillator –Move it slightly to the left and down several inches toward the feet

61. © 2005 by Thomson Delmar Learning,a part of The Thomson Corporation. All Rights Reserved 61 Special Situations  Medication patches –Remove medication patches prior to defib  Hypothermia –Cold heart is resistant to attempts at defib –One set of stacked shocks only

62. © 2005 by Thomson Delmar Learning,a part of The Thomson Corporation. All Rights Reserved 62 Special Situations  Pediatric considerations –Under 55 lb (25 kg) or 9 years old: defib with a machine designed for pediatric use Over 1 year old: Use adult AED if only machine at hand

63. © 2005 by Thomson Delmar Learning,a part of The Thomson Corporation. All Rights Reserved 63 Cardiac Arrest  Transport –Transport quickly to closest appropriate hospital –Request ALS backup

64. © 2005 by Thomson Delmar Learning,a part of The Thomson Corporation. All Rights Reserved 64 Cardiac Arrest  Postarrest care –Prepare to provide ventilations using a bag-valve-mask –Adequate breathing: use high-flow oxygen, non-rebreather mask –Unconscious but no trauma suspected: consider placing in recovery position

65. © 2005 by Thomson Delmar Learning,a part of The Thomson Corporation. All Rights Reserved 65 Cardiac Arrest  Ongoing assessment –Monitor patient closely during transport in case of another arrest

66. © 2005 by Thomson Delmar Learning,a part of The Thomson Corporation. All Rights Reserved 66 Cardiac Arrest  Field termination –Resuscitative efforts are not indicated in cases where death is obviously irreversible –Consult local protocols for field termination procedures –Offer support to the family and friends present –Show respect for the dead

67. © 2005 by Thomson Delmar Learning,a part of The Thomson Corporation. All Rights Reserved 67 Postcall  Document thoroughly all actions or nonactions taken  Replenish supplies

68. © 2005 by Thomson Delmar Learning,a part of The Thomson Corporation. All Rights Reserved 68 Postcall  Maintain competency in AED use –A semiannual refresher course in AED use is a minimum expectation for many EMTs  Debriefing

69. © 2005 by Thomson Delmar Learning,a part of The Thomson Corporation. All Rights Reserved 69 Stop and Review  What does the EMT need to do before pressing the Shock button on the AED?  What are two important safety considerations when shocking a patient?